In 1998, Pfizer launched Viagra, a prescription drug for erectile dysfunction, to great success in the US and Europe. But when the pharmaceutical giant introduced the drug to China, it became entangled in an 11-year battle with local drug companies over its patent, its three-dimensional trademark, and the drug's Chinese trademark. The prevalence of counterfeits and of herbal substitutes containing Viagra's active ingredient also hurt sales. In this case, students analyze the shortcomings of Pfizer's market-entry strategy, propose ways it can generate sales before its patent expires, and consider actions it should take in the future to protect its intellectual property rights.